Means for regulating the superheater temperature of the steam in locomotive engines



b- 1933- J. MADEYSKI MEANS FOR REGULATING THE SUPERHEATER TEMPERATURE OF THE STEAM IN LOCOMOTIVE ENGINES Filed Nov.

Patented Feb. 28, 1933 UNITED STATES PATENT series JULIAN MADEYSKI, OF WARSAW, POLAND, ASSIGNOR TO "WARSZAWSKA SIPOLIKA AKGYJNA IB'U'DOWY PAROWOZOW', OF WARSAW, POLAND, A JOINT-STOCK COMPANY OF POLAND MEANS FOR REGULATINGv THE SUPERHEATER TEMPERATURE OF THE STEAM IN LOCOMOTIVE ENGINES Application filed November 30, 1927, Serial No. 236,865, and in Poland December 4, 1926.

This invention relates to that class of apparatus for regulating the temperature of superheated steam for locomotives with large tubular superheaters.

The present locomotives, with larger tubular superheaters have the drawback that in their case the superheating temperature is dependent upon the rate of combustion in the grate. In the case of a high rate of combustion in the grate it reaches the desired degree, whilst with lower rates of combustion it is too low, and this is detrimental to the consumption of steam per horse power per hour, increasing the consumption of water and coal, because, at the lower rates of combustion in the grate, the heated fluids flow too slowly through the fine and smoke tubes and because the transmission of heat to the heating surface of the tube is the more unsatisfactory, in proportion as'the stream of gases flows less rapidly. With existing boilers too little heat is communicated to the superheater, in other words, the steam the moisture content of which with a high level of water in the boiler may amount to from 16 to 25 per cent, is not sufficiently superheated.

This phenomenon is due to the construction or the large tube superheaters, because only a portion-from 40 to 60 per cent.-of

the gases of combustion passes through the smoke tubes having superheater elements, whilst the other portionfrom 60 to per cent-passes through the fire or flame tubes, so that with the lower and intermediate rates of combustion in the grate, a too small amount of heat reaches the superheater elements and the superheated steam does not reach the desired higher extreme of temperature.

The object of the presentinvention is to obviate these drawbacks by so arranging that at the lower and intermediate rates of combustion in the rate, the fire or flame tubes are more or less closed by one or a plurality of flaps turning about horizontal axes or by some other suitable controlling means, preferably located in the smoke chamber, so that the whole volume of the products of combustion developed in the grate may be caused to stream through the smoke tubes, in which the superheater elements are located, thus communicating to these latter the requisite amount of heat for superheating the steam to the desired high temperature.

In the case of overheating on the other hand, an appropriate amount of the gases may be caused to pass through the fire or flame tubes by raising or opening the regu lating device or devices, so that in this way the temperature of superheating does not exceed the desired upper temperature.

The operation of the flap or flaps or equivalent devices may be effected by hand from the drivers or stokers stand, or automatically through the action of the draught tube or by means of differential pistons, the smaller surfaces of which are under the steam pressure in the valve chest, while the larger surfaces are under the steam pressure in the draught pipe.

With the foregoing construction the material saving of water and therefore of an equivalent quantity of coal is effected, because the locomotive can be always working with superheated steam.

A further characteristic of the invention relates to improvements concerning the elficiency of the superheater, which is divided into two parts and about one third of the superheater elements are employed for drying steam with tubular elements arranged in parallel and the remaining two thirds constitute actual superheaters, so that by this arrangement of the tubes in succession, better drying and superheating of the steam is ensured.

In order that the invention may be clearl understood a constructional embodiment wi 1 now be described with reference to the accompanying drawing, in which Figure 1 is a diagrammatic elevation, partly in section, of parts of a locomotive engine provided with apparatus constructed and arranged in accordance with this invention.

Figure 2 is a detail vertical section of the superheater box on a plane at right angles to that of Figure 1.

The damp steam passes from the boiler through the conduit 1 to the first superheater chamber and thence to the U shaped bent tubes 19, located in pairs side by side in the smoke tubes. Their ends open into the chamber 2 of the superheater. The damp steam passin through the said tubes 19 from the con uit 1 to the chamber 2 is perfectly dried. It then passes throu h a regulator 3 to the chamber 4 to which t e ends of the superheater elements 20 are connected.

Passing through the pipes 20, the steam be comes superheated to the desired high temperature and then passes to the chamber 5 from which it is supplied to the cylinders of the engine. 1

This passage of the steam takes place in 'a known way, The superheater pig es are arranged in two groups 19 and 20. he superheater is divided into two chambers 2 and4. The superheater pipes 19 receive the wet steam from the pipe 1 and forward this steam in dr condition to the superheater chambers 2. he d steam flows through the regulator 3 into t e second chamber 4 of the superheater box. The superheater pipe 20 terminates in the chamber 4. The ends of these superheater elements are connected with a channel 5, which is located adjacent the chamber 4 but this arrangement is not shown in the drawing since it is well known.

For r latmg or controlling the division or distri ution of the heat conducted to the tubular elements, a flap 7 is provided turning upon a pivot 8. At the lower and intermedata rates of combustion, the flap closes all the fire or flame tubes located below the smoke tubes, the result being that the products of combustion developed in the grate are drawn almost I entirel through the smoke tubes, with greater ve ocity than with ordinary boilers, so that the desired temperature for drying and superheating the steam is obtained.

At higher rates of combustion in the grate, the flap 7 is so operated that when excessive superheating occurs, or the temperature rises above that which is required, the flap is more or less raised.

This can be effected from the stokers post by hand, or it may be controlled by the draught steam tube, or by means of differential pistons 10, the result being that when at rest and running light the locomotive has the flap 7 entirely raised by the influence of a counterpoise weight 9, and the flow of the gases through the flame or fire tubes is unobstructed.

On the other hand when the locomotive is working with a heavier load, the flap 7 is so 0 rated from the steam piston 10 by means 0 a lever 13 pivoted at 11 that with lesser and intermediate working or firing of the engine the flame tubes are closed. 'With increased load owing to the differential operation of the pistons, the working is so controlled that only that portion of the gases is allowed to pass through the flame or fire tubes which is necessary for the satisfactory development of damp steam and the attainment of the desired maximum superheater temrature.

In the differential device shown the piston 12 is in communication with the valve chest 6 through a pipe 16 whilst the piston 14 is in communication with the draught steam pipe 17 through the tube 18.

The force acting on the piston 12 through steam pressure must perform several functions. It must counterbalance the counterweight 9. It must equalize the pressure difference between fire pipe and steam chamber, which difference acts on the valve 7 and finally it must counterbalance the steam pressure on the piston 14 through the exhaust steam, thereby holding the valve 7 closed until the consumption of steam in the locomotive has advanced far enough to produce excess superheater steam in the superheater elements.-

When the engine is at low load, that is, when the regulator or overnor of the locomotive is gradually opene only the steam pressure on the piston 12 is so reat that the valve 7 completely closes the ower smoke pipe. Only when the regulator is open entirely and the pressure in the valve box is highest the regulating valve 7 begins to move. At this instance the consumption of steam, the charge on the grate and the heat generated is so great" that with a constant cross section of the blow pipe the tension will advance be ond a certainlimit for instance 0.4 atmosp eres. The

pressure difference between piston 12 and 14 therefore becomes gradually greater for the pressure in the valve box is maximum pressure and cannot be increased. It could possibly go down'while in the blow pipe the steam pressure will increase the more the greater the flow of steam which passes through the same per second. From this instance on the operation is automatic.

It will be understood that the counter weight 9 has a permanent tendency to maintain the flap 7 always in the horizontal dotted position shown in the drawing, that is, in open position. In this position the combustion gases would not flow through the upper tubes, which tubes are provided with superheater elements, but the gas would flow through the lower smaller tubes which do not have the superheater elements. This position of the flap 7 is occupied when the locomotive is being fired up and while it is still standing in 1 the roundhouse or on the track.

The flap 7, however, is additionally controlled by the double piston 12, 14. The piston rod of this double piston or plunger is engaged by the lever 13. This lever has a fixed fulcrum and at one end is provided with a slot 15 engaging an arm 7 of the flap 7. The smaller one of the double pistons, namely the piston 12, isacted on by the steam pressure in the valve box or casing 6, because the cylinder of this smaller piston is connected with the valve housing 6 through the pipe 16. The larger piston 14 is acted on from the opposite side by the pressure of the steam flow ing through the blow off 17 since this blow oil is connected with the cylinder of this greater piston by means of the pipe 18. When the locomotive stands still and when there is no steam in the valve housing 6 and when at this time also the blow oil is not in operation, no

10 forces whatsoever act on the pistons 12, 14:.

It is, therefore, under these conditions solely the counterweight 9 which controls the flap 7 and which maintains this flap in open position.

15 If the locomotive, however, travels at very low load or moderate load, that is, when the fire on the grate is moderate only, the steam in the valve housing 6 will have full pressure. The blow ofi 17 however, will have hardly 20 any pressure or no pressure whatsoever. The steam pressure from the valve housing 6 will then act on the smaller piston 12, to force the same downward, thereby overcoming the force of the counterweight 9. In this manner the flap 7 is closed and it remains closed while the locomotive is travelling at low load or moderate load.

What I claim and desire to secure by Letters Patent in the United States of America is 1. A locomotive boiler having tubes provided with superheating elements and tubes unprovided with superheating elements, a counterbalanced damper for the last named tubes arranged for operation by differences of pressure in the fire box and smoke box, and

means, actuated by difi'erences in pressure between the steam chest and the exhaust discharge nozzle to close the damper.

2. In a locomotive engine of the type described, upper fire tubes, having drying and superheating elements and lower fire tubes not so provided and means for obstructing to any required extent the passage of products of combustion through such lower fire tubes in order to divert the products of combustion to a required degree through the tubes containing the drying and superheating elements, said obstructing means comprising a damper for closing the openings of said lower tubes, and

i} mechanism for operating said damper and comprising a differential piston the smaller surface of which is in connection with the steam chest and the larger surface of which is connected with the suction draft steam tube.

In witness whereof I aflix my signature.

J ULJ AN MADEYSKI. 

